Start by heating the olive oil in a large skillet over medium heat. Once the oil is shimmering, add the lean ground beef. Use your wooden spatula to break it up as it cooks, until browned and cooked through, about 5-7 minutes.
Once the beef is browned, add the taco seasoning, cumin, and a pinch of cayenne if desired. Stir well to coat the beef evenly with the spices, allowing everything to cook together for another minute or so to enhance the flavors.
Pour in the uncooked pasta and the water. Stir to combine, making sure the pasta is submerged in the liquid. Bring the mixture to a gentle boil.
Once boiling, reduce the heat to a simmer and add the frozen corn, diced tomatoes (with their juices), and the black beans. Stir everything together and cover the skillet with a lid.
Let the pasta cook for about 10-12 minutes, stirring occasionally, until the pasta is tender and has absorbed most of the liquid. If it seems too dry, feel free to add a splash of water.
Remove the skillet from the heat and sprinkle the shredded Mexican cheese blend on top. Cover the skillet again for a few minutes to let the cheese melt into a gooey, delicious layer.
Once the cheese is melted, give everything a gentle stir to mix it all together. Serve hot, topped with a dollop of sour cream and a sprinkle of sliced green onions for a fresh touch.